libstudxml is a streaming XML pull parser and streaming XML serializer implementation for modern, standard C++. It has an API which the authors believe should have already been in Boost or even in the C++ standard library. It is compact, external dependency-free, and reasonably efficient. The XML parser is a conforming, non-validating XML 1.0 implementation which is based on tested and proven code.

The Link Grammar Parser (link-grammar) is a syntactic parser of English, Russian, Arabic, and Persian (and other languages as well), based on link grammar, an original theory of English syntax. Given a sentence, the system assigns to it a syntactic structure, which consists of a set of labelled links connecting pairs of words. The parser also produces a "constituent" (Penn tree-bank style phrase tree) representation of a sentence (showing noun phrases, verb phrases, etc.). The RelEx extension provides dependency-parse output.

gradle-sablecc-plugin is a gradle plugin which creates parsers using SableCC. SableCC supports automatic CST-to-AST transformation, emits all the visitor patterns and analysis helpers you will likely ever need, and is LR, not LL(k). Many example grammars are available for modern languages; the author of this plugin has written dozens.

GrammarScope provides a simple-to-use graphical interface to the parse tree, grammatical structure, typed dependencies, and semantic graph of any text as parsed by the Stanford Parser/Stanford CoreNLP.

pyC11 is a grammar to parse programs in the C programming language following ISO/IEC 9899:2011. It is written using pyPEG, a parsing framework for Python. The grammar supports Python 2.7 and 3.x. The test bench requires py.test.

lihata is a compact textual language which can represent a tree of lists,
hashes,
and tables.
The syntax tries to be minimal and flexible to allow formatting a lihata file to fit the
context it represents.
The source release contains an event and DoM parser and helper functions for maintaining
lihata trees.
lihata is a convenient language for both simple and complex configuration files and text
representation of data files.

Metrix++ is a platform to collect and analyze code metrics. It has a plugin-based architecture, so it is easy to add support for new languages, define new metrics, and/or create new pre- and post-processing tools. Every metric has 'turn-on' and other configuration options. There are no predefined thresholds for metrics or rules; you can choose and configure any limit you want. It scales well to large codebases. For example, initial parsing of about 10000 files takes 2-3 minutes on an average PC, and only 10-20 seconds for iterative re-run. Reporting summary results and exceeded limits takes less than 1 - 10 seconds. It can compare results for 2 code snapshots (collections) and differentiate added regions (classes, functions, etc.), modified regions, and unchanged regions. As a result, easy deployment is guaranteed into legacy software, helping you to deal with legacy code efficiently, and either enforce the 'leave it not worse than it was before' rule or motivate re-factoring.

PHP Emoticon Parser can replace emoticon text with HTML image tags. It can search for emoticon text characters in a given text string and replace them with equivalent emoticon images. The emoticon text and image mappings are defined in a separate script that maps emoticon names to the different equivalent representations for emoticon text symbols.